Sheet-conveying device

ABSTRACT

A conveying device for conveying sheets of cardboard, paper, or synthetic plastic foil upon a table of a sheet processing machine and into abutment with front and/or side stops on the table effects correct location of the sheets with respect to the stops by airflows directed upon the sheets from below. These airflows constitute moving air cushions supporting and conveying the sheets toward the stops and retaining the sheets in abutment therewith.

United States Patent inventor Bernd Schwebel Offenbach am Main, GermanyAppl. No. 817,679 Filed Apr. 21, 1969 Patented Nov. 30, 1971 AssigneeMabeg Maschinenbau GmbH, Nachi.

Hense 8; Pleines GmbH 8: Co. Oflenbnch am Main, Germany Priority May 24,1968 Germany P 17 61 468.5

SHEET-CONVEYING DEVICE 4 Claims, 4 Drawing Figs.

u.s. Cl 271/74, 271/48, 271/58 rm. Cl B65b 29/24 Field of Search 271/48,49, 50, 58-60, 74

m M f 1 5 [56] References Cited UNITED STATES PATENTS 98,253 12/1909Turner 271/74 3,268,222 8/1966 Off 271/74 3,173,683 3/1965 Tebbs 271/603,336,026 8/1967 Preuss 271/60 3,342,480 9/1967 Camerini.. 271/583,463,482 8/1969 Baron 271/59 Primary Examiner-Harvey C. HomsbyAttorney-Hane and Baxley ABSTRACT: A conveying device for conveyingsheets of cardboard, paper, or synthetic plastic foil upon a table of asheet processing machine and into abutment with front and/or side stopson the table effects correct location of the sheets with respect to thestops by airflows directed upon the sheets from below. These airflowsconstitute moving air cushions supporting and conveying the sheetstoward the stops and retaining the sheets in abutment therewith.

PATENTEDNB 30 3, 624. 807

SHEET 2 BF 2 lave/liar:

Bwmuo Sam was SHEET-CONVEYING DEVICE The invention relates to aconveying device for sheets made of cardboard, paper, synthetic plasticfoils, etc., for moving said sheets either following each other or inoverlapped or shingled arrangement, and more particularly, to aconveying device for moving the sheets into abutment with stops on atable of a sheet-processing machine.

BACKGROUND There are known sheet-conveying means of the general kindabove referred to in which the sheets are moved by conveyor bands,rollers or grippers, or by means of pneumatic bands and suction meanstoward and into engagement with front stops on the table and are pushedor pulled by means of rails, rollers, grippers or other mechanical meanstoward the side stops on the table and located in registry therewith.

To obtain clean and fully acceptable prints it is essential that thesheets are not only placed exactly in registry with both the front stopsand the side stops, but that they also remain correctly located untiltransferred to the printing press proper.

The very high operational speed of modern printing presses and theresulting reduction in size of all the cylinders of the press entailsthat only a very short period of time can be allocated for the requiredsheet-locating operations. It has been attempted to overcome theresulting problem by reducing the initially high speed of the sheetmovement by special delay means just before the sheets reach the stopsso that they engage the stops with a comparatively soft impact. However,it has been found that in spite of a reduction of the speed of the finalsheet movement, there is a tendency of the sheets to bounce back fromthe stops.

The problem of correctly locating the sheets is not only present at thefront stops which are engaged by the leading edge of the sheets, thatis, by head-on collision, but also at the side stops due to thetremendously high operational speeds of THE INVENTION It is a broadobject of the invention to provide a novel and improved sheet-conveyingdevice of the general kind above referred to which conveys the sheetsgently into engagement with the front and/or side stops and retains thesheets in such engagement until they are transferred to the printingpress proper.

SUMMARY OF THE INVENTION The aforepointed out object, feature andadvantage, and other objects, features and advantages which will bepointed out hereinafter, are obtained by directing flows of pressure airupon the sheets from below during the last part of the move ment of thesheets toward the stops. These airflows constitute in effect aircushions upon which the sheets float toward the stops without harshimpact therewith. The airflows also retain the sheets in position as themoving action thereof is continumg.

The invention also provides that the direction of the airflow withrespect to the locations of the stops is adjustable by means of varyingthe angular positions of the nozzles from which the airflows emanate,either singly or jointly.

DESCRIPTION OF A PREFERRED EMBODIMENT In the accompanying drawing, apreferred embodiment of the invention is shown by way of illustrationand not by way of limitation.

In the drawing:

FIG. 1 is an elevational diagrammatic sectional view of asheet-conveying device according to the invention;

FIG. 2 is a plan view ofFlG. 1;

FIG. 3 is a diagrammatic elevational view, partly in section showingmovements of sheets from a stack of sheets to the conveying device; and

FIG. 4 is an edge view seen in the direction of an arrow in FIG. 1.

Referring now to the figures more in detail, FIG. 3 shows a sheet stacktable assembly 20, which should be visualized as being equipped withconventional means for lifting and lowering the stack, and also with asuction head for supplying sheets l8, 19 to a sheet table 1 in aconventional fashion. This sheet table coacts with the sheet-conveyingdevice according to the invention which comprises a table 2 on whichfront stops 3 and side stops 4 are mounted, either rigidly or movably.Side stops 4 are preferably provided with a guide such as a guide 5 madeof sheet metal to assure that sheets such as sheet 19 are guided towardthe front stops.

Table 2 has fitted therein two or more nozzle assemblies, four nozzleassemblies 6, 7, 8 and 9 being shown by way of example. The airflowsemanating from the nozzle assemblies are directed toward front stops 3and if desired also toward side stops 4.

The nozzle assemblies should be visualized as being of conventionaldesign and connected to suitable pressure air conduits (not shown). Theyare preferably rotatably mounted within the table so that the angularpositions of the nozzle assemblies can be adjusted. Adjustment can beeffected for each nozzle assembly individually, or all or some of thenozzle assemblies can be ganged for joint adjustment.

Suitable adjustment means can be readily visualized. There is shownbyway of example a common shaft 12 which, via a gear 10 and a worm I1 iscoupled to each of the four nozzle assemblies. A hand wheel 13 serves toturn the shaft and thus I the nozzle assemblies as desired. The handwheel is advantageously so placed that the nozzle assemblies can beadjusted when and while they are in operation.

The exits of the noule assemblies are preferably so ar ranged that airemanates from each nozzle assembly in the manner of an air sheet, as itis indicated at l4, l5, l6 and 17. As is evident, the nozzle assembliesmay be disposed in one or more rows and such rows may be parallel toeach other.

The operation of the conveying device as hereinbefore described is asfollows:

Sheets are conveyed either one after the other or in overlapping orshingled arrangement by suitable and conventional conveying means towardfront stops 3. As a sheet such as sheet 18 comes within the range ofairflows l4, 15, I6 and 17, it is carried by these airflows in themanner of moving air cushions toward the front stops 3 and also towardabutment with side stops 4. The continuing moving action of the airflowsmaintains the sheets in abutment with the stops until the sheets aregripped by gripping means of the printing press.

What is claimed is:

l. A conveying device for sheets of cardboard, paper or syntheticplastic foils for moving sheets into abutment with sheet stops on atable of a printing press, and said device comprising in combination:

a table having stationarily mounted thereon front stops and side stopsfor respectively lengthwise and sidewise locating sheets fed upon thetop surface of the table and conveyed thereon toward the stops;

nozzle means rotatably mounted in said table substantially flush withthe top surface thereof and disposed anteriorly of said stops as seen inthe direction of conveyance of the sheets, said nozzle means beingoriented to direct airflows substantially parallel to the plane of thetable surface and toward the front stops and the side stops forfloatingly conveying sheets along the table surface into engagement withsaid front stops and side stops and retaining the sheets in saidengagement;

table surface and aligned for producing sheetlike airflows substantiallyparallel to the plane of sheets on sheet-like table.

3. The conveying device according to claim I. wherein said nozzle meanscomprise a plurality of spaced-apart nozzles disposed crosswise of thewidth of the table surface.

4. The conveying device according to claim 3, wherein at least some ofsaid nozzles are ganged. and wherein said setting means are operativelyconnected to said ganged nozzles for l O jointly turning the same.

1. A conveying device for sheets of cardboard, paper or syntheticplastic foils for moving sheets into abutment with sheet stops on atable of a printing press, and said device comprisiNg in combination: atable having stationarily mounted thereon front stops and side stops forrespectively lengthwise and sidewise locating sheets fed upon the topsurface of the table and conveyed thereon toward the stops; nozzle meansrotatably mounted in said table substantially flush with the top surfacethereof and disposed anteriorly of said stops as seen in the directionof conveyance of the sheets, said nozzle means being oriented to directairflows substantially parallel to the plane of the table surface andtoward the front stops and the side stops for floatingly conveyingsheets along the table surface into engagement with said front stops andside stops and retaining the sheets in said engagement; setting meansincluding rotating drive means for selectively rotating said nozzlemeans to vary the directional orientation of the nozzle means and thusof airflows emanating therefrom relative to the stops; and actuatingmeans disposed spaced apart from said table and including linkage meanscoupled with said drive means for operating the latter when and whilesheets are being conveyed without interference with the conveyance ofthe sheets.
 2. The conveying device according to claim 1, wherein saidnozzle means include a plurality of nozzle exits included in the tablesurface and aligned for producing sheetlike airflows substantiallyparallel to the plane of sheets on sheet-like table.
 3. The conveyingdevice according to claim 1, wherein said nozzle means comprise aplurality of spaced-apart nozzles disposed crosswise of the width of thetable surface.
 4. The conveying device according to claim 3, wherein atleast some of said nozzles are ganged, and wherein said setting meansare operatively connected to said ganged nozzles for jointly turning thesame.